Trunking and coupling means therefor

ABSTRACT

A section of waterproof trunking ( 30 ) has an elongate tubular member ( 32 ) of rectangular cross section, two opposing sides of which have holes ( 34 ) with screws therein. These holes act as means for attaching member ( 32 ) to further members ( 32   a ) and/or ( 32   b ). Member ( 32 ) also has an aperture ( 36 ) in one side. Aperture ( 36 ) has a length L 1  which is substantially less than the length L 2  of member ( 32 ), this length being measured axially along member ( 32 ). Aperture ( 36 ) also has dimension L 3  which is measured perpendicular to L 1  and L 2 , and this length is equal to or slightly less than length L 4 , the external dimension of member ( 32 ) measured in the same direction. Trunking section ( 30 ) also has closure means ( 38 ) for the or each aperture ( 36 ). Closure means ( 38 ) has a cover plate ( 40 ) which is attached to member ( 32 ) by use of screws ( 42 ) through holes ( 43 ) and into threaded holes ( 44 ). Plate ( 40 ) is also provided with a neoprene sealing gasket ( 46 ).

The present invention relates to trunking and coupling means therefor,and particularly, not exclusively, to waterproof trunking for carryingelectrical cables.

The carrying of electrical cables in a network of trunking is used inmany industries. In the food, beverage and pharmaceutical industries,where hygiene is of paramount importance, stainless steel trunking isregularly used. It is important that such trunking is easily cleaned andthat places where dirt may gather, and infestation:may occur, are keptto a minimum.

In some situations it is necessary to provide a waterproof trunking. Forexample, where trunking is located near a high ceiling the preferredmethod of cleaning maybe to direct a jet of water at the trunking fromthe ground. As a result, the term waterproof is used within thisdocument to refer to the amount of sealing of joints that is required,between parts of the trunking, in order to prevent water penetratingunder the circumstances of this type of cleaning.

An example of a trunking system of this type is shown in FIG. 1. Thetrunking shown consists of elongated trunking members 10 and 12 havingrespective lids 14 and 16. Each lid is retained in position by screws 18and the junction between members 10 and 12 and respective lids 14 and 16is sealed with a gasket (not shown). In order to provide an adequateseal for the waterproofing required it is necessary to provide a largenumber of screws 18. If only a few screws 18 are used the lids 14 and 16buckle along their edges, providing gaps which allow water inside thetrunking members 10 and 12. As a result of the large number of screwsused to provide this seal, the time taken to install this waterprooftrunking is significant.

A coupling 20 is used to join trunking members 10 and 12. The coupling20 consists of first coupling plate 22, attached to trunking member 10and a second coupling plate 24 attached to trunking member 12. Betweencoupling plates 22 and 24 is a gasket seal 26. The coupling plates 22and 24 are fixed together using screws in holes 28. This form ofcoupling creates a significant number of dirt traps around the edge ofplates 22 and 24 and in holes 28. The gasket 26 is also exposed aroundall of the edge of plates 22 and 24, providing a further dirt trap.

Preferred embodiments of the present invention seek to overcome theabove described disadvantages of the prior art.

According to an aspect of the present invention there is provided asection of waterproof trunking comprising:—

-   -   at least one elongate tubular member of substantially        rectangular cross-section having attaching means for attaching        the or each said member to at least one further member and        having at least one aperture in at least one respective side of        said member for providing access to the interior of, said        member, wherein the or each said aperture has a length less than        the length of the or each said side measured in an axial        direction along said tubular member and has a dimension less        than the dimension of said side measured transverse to said        axial direction; and    -   respective closure means for the or each said aperture.

By having a trunking member with small apertures in at least one sideand closure means therefor, provides the advantage that the majority ofany trunking member is entirely sealed along its length at all times.Therefore, the only points at which potential leaks may be found arearound the closures to the aperture and the joints between adjacentmembers and any couplings therebetween. The advantage is also providedthat the number of securing screws is significantly reduced, therebyreducing the time required to install the trunking as well as reducingthe number of potential dirt traps which require cleaning.

In a preferred embodiment the attaching means includes at least one holein said member adapted to receive a respective screw or bolt forretaining the member in position relative to a further member.

In another preferred embodiment the attaching means is at least onethreaded member extending internally from said member and adapted toengage a coupling internally of said member, said coupling having slotstherein allowing said threaded members to pass along said slots.

By providing the member with internally located threaded engaging meansand slots in the coupling, the advantage is provided that the trunkingmember is provided with even fewer holes on its external surface therebyreducing the number of dirt traps.

The closure means may comprise a plate adapted to cover said aperture.

In a preferred embodiment said plate is provided with a plurality ofholes adapted to receive respective screws or bolts therein for engagingwith said member.

The closure means may further comprise a sealing gasket located betweensaid plate and said member.

In a preferred embodiment the axial length of the aperture is less than50% of the axial length of the member.

In another preferred embodiment the axial length of the aperture is lessthan 20% of the axial length of the member.

According to another aspect of the present invention there is provided acoupling for joining at least one first tubular waterproof trunkingmember of substantially rectangular cross section to at least one secondtubular waterproof trunking member of substantially rectangular crosssection, the coupling comprising:—

-   -   a body adapted to extend within the or each first and second        member;    -   retaining means for retaining said body and the or each said        member together; and    -   at least one extension portion extending around said body and        adapted to form a substantially continuous surface between a        surface of said coupling and at least one surface of the or each        first member and between a surface of said coupling and at least        one surface of the or each second member.

By providing a coupling as described above, the advantage is providedthat a tubular trunking, of the type described above, can be used, andcan provide a waterproof seal between adjacent members. Providing asubstantially smooth and continuous surface at the junction between thecoupling and the member reduces the number of potential dirt traps.

In a preferred embodiment, edges of said body are shaped so as toprovide a substantially smooth transition between an internal surface ofthe trunking member and a respective internal surface of the body.

In another preferred embodiment said edges are curved.

The retaining means may comprise a hole in said body adapted to alignwith a hole in a trunking member and adapted to receive a screw or bolttherein.

The hole may further comprise an internal thread.

In a preferred embodiment, said extension portion is provided with atsealing means for sealing between the trunking member and the extensionportion.

The sealing means may comprise a gasket attached to said extensionportion.

According to a further aspect of the present invention there is provideda coupling means for joining at least one first tubular waterprooftrunking member having a rectangular cross section to at least onesecond tubular waterproof trunking member having a rectangular crosssection, the coupling means comprising:—

-   -   a body adapted to extend, within the or each first and second        member;    -   retaining means for retaining said body and the or each said        member together; and    -   sealing means extending around said body and adapted to provide        a seal between the or each said first and second member.

By providing a sealing means extending around the body adapted to extendwithin first and second trunking members, the advantage is provided thata waterproof seal can be provided between adjacent members and thetransition from one trunking member to the next can be provided in analmost continuous surface with a minimum number of dirt traps.

In a preferred embodiment edges of said body are shaped so as to providea smooth transition between an internal surface of the trunking memberand a respective internal surface of the body.

By providing such a smooth transition, the advantage is provided that ascables are pushed along a section of trunking and over a transition to anext section of trunking the coupling means provides little obstacle tothat cable as it passes through.

In another preferred embodiment said edges are curved.

According to another aspect of the present invention there is provided acoupling for joining at least one first tubular waterproof trunkingmember of substantially rectangular cross section to at least one secondtubular waterproof trunking member of substantially rectangular crosssection, the coupling means comprising:—

-   -   a tubular body, adapted to extend at least partially over the or        each first member and at least partially over the or each second        member;    -   retaining means for retaining said body and the or each said        member together; and    -   sealing means for sealing a junction between the first and        second members.

By providing a tubular coupling extending partially over the twotrunking members being joined together, the advantage is provided thatthe junction between the first and second trunking members is completelycovered, and completely sealed and a relatively smooth external surfacehaving few dirt traps can be provided. The above coupling also has theadvantage that the internal surface of the transition between the firstand second trunking members is smooth thereby allowing free motion ofthe cables along the trunking members.

In a preferred embodiment at least one edge of at least one surface ofsaid body is curved.

According to another aspect of the present invention there is provided acoupling for joining at least one first trunking member having a lidthereon to at least one second trunking member having a lid thereon, thecoupling comprising:—

-   -   a body, adapted to extend at least partially within the or each        first and second member;    -   first retaining means for retaining said body and the or each        said member together;    -   receiving portion adapted to receive all except one edge of        surfaces at an end of said member and said respective lid;    -   clamping means adapted to be located over said edge of said        member and lid not received in said receiving portion; and    -   second retaining means for retaining said clamping means and        said retaining portion together.

By providing a coupling as described above the advantage is providedthat the clamping means is able to assist in holding the lid of thetrunking section in position. In particular, this is advantageous when awaterproof seal is required since the receiving portion can provide awaterproof seal between the adjacent trunking members and the clampingmeans provides a seal between the adjacent lids. The clamping means alsomaintains the sealing along the join between the member and the lid tothe very end of the member and lid.

In a preferred embodiment the body consists of four surfaces.

By providing the body of the coupling with four surfaces, i.e. includingan upper part adjacent the clamping means, the advantage is providedthat a better seal between the adjacent lids is provided. However, wherethree surfaces are provided on said body easier access to the cables isprovided once the clamping means has been removed.

According to another aspect of the present invention there is provided atrunking apparatus comprising:—

-   -   at least one trunking section substantially as described above;        and    -   at least one coupling substantially as described above.

Preferred embodiments of the present invention will now be described, byway of example only, and not in any limitative sense, with reference tothe accompanying drawings in which:—

FIG. 1 is a perspective view of trunking members and a coupling of theprior art;

FIG. 2 is a perspective view of trunking sections of a first embodimentof the present invention;

FIG. 3 is a perspective view of a coupling and trunking members of asecond embodiment of the present invention;

FIG. 4 is a perspective view of a coupling and trunking members of athird embodiment of the present invention;

FIG. 5 is a perspective view of a coupling and trunking members of afourth embodiment of the present invention;

FIG. 6 is a perspective view of a coupling and trunking members of afifth embodiment of the present invention;

FIG. 7 is a perspective view of a coupling and trunking members of asixth embodiment of the present invention;

FIG. 8 is a perspective view of a coupling and trunking members of aseventh embodiment of the present invention;

FIG. 9 is a plan view of the coupling and trunking sections of FIGS. 7or 8; and

FIG. 10 is a plan view of a coupling and trunking members of an eighthembodiment of the present invention.

Referring to FIG. 2, a section of waterproof trunking 30 has an elongatetubular member 32 of rectangular cross section, two opposing sides ofwhich have holes 34 with screws therein. These holes act as means forattaching member 32 to further members 32 a and/or 32 b. Member 32 alsohas an aperture 36 in one side. Aperture 36 has a length L₁ which issubstantially less than the length L₂ of member 32, this length beingmeasured axially along member 32. Aperture 36 also has dimension L₃which is measured perpendicular to L₁ and L₂, and this length is equalto or slightly less than length L₄, the external dimension of member 32measured in the same direction. Trunking section 30 also has closuremeans 38 for the or each aperture 36. Closure means 38 has a cover plate40 which is attached to member 32 by use of screws 42 through holes 43and into threaded holes 44. Plate 40 is also provided with a neoprenesealing gasket 46.

In use, a trunking member 32 is attached to further trunking members 32a and 32 b by use of an internal coupling means (not shown) and held inposition the by screws in holes 34. The person installing the trunking,and cabling therein, inserts his hand within aperture 36 and uses thisaperture to access the cables inside. When installing a new cable, thecable is passed from one aperture to the next. Once all the cables areinstalled the closure means 38 are used to cover apertures 36. Plate 40is placed over aperture 36 and screws 42 are inserted through holes 43into threaded holes 44. Gasket 46 provides a waterproof seal to thetrunking section.

An alternative coupling device might be external of the members 32, 32 aand 32 b.

Referring to FIG. 3, a coupling 50 for joining a first tubularrectangular waterproof trunking member 32 to a second tubularrectangular waterproof trunking member 32 a the coupling having a body52, which extends within the first and second members 32 and 32 a, andretaining means in the form of threaded holes 54.

Holes 54 are adapted to receive screws 55. Coupling 50 also has anextension portion 56 extending around the body 52. Extension portion 56is formed such that a surface 58 will, in use, form a substantiallycontinuous surface with surface 60 of member 32 and surface 62 of member32 a. Similarly surface 64 of extension portions 56 forms asubstantially continuous surface with surface 66 of member 32 andsurface 68 of member 32 a. Extension portion 56 is also provided with.neoprene gasket 70.

In use, body 52 of coupling 50 is inserted within member 32. Screws 55are inserted through holes 34 and into threaded holes 54 and tightenedso as to provide a strong mechanical joint. Because the coupling 50,member 32 and screw 55 are all formed from stainless steel a goodelectrical contact is provided between all of these parts and as aresult an earth continuity between trunking sections can be maintained.Similarly member 32 is inserted over body 52 such that holes 34 and 54are aligned and screw 55 is inserted and tightened.

As an alternative, the extension portion 56 maybe entirely formed from aneoprene gasket. This would require that the extension portion be muchnarrower than that shown so that an almost continuous surface betweenthe surfaces 60 and 66 of member 32, and 62 and 68 of member 32 a couldbe formed. Ideally the edges of and surfaces 60 and 62, and 66 and 68would be shaped so as to receive the gasket leaving as little neopreneexposed as possible. For example if these edges were given concavesurfaces they would provide a suitable seal with a gasket of circularcross-section.

An alternative variation of this coupling is shown in FIG. 4. In thisembodiment the retaining means, shown as holes 34 in FIG. 3, arereplaced by slots 72 in body 52. Members 32 and 32 a are provided withthreaded lugs internally of the members, which are not shown on FIG. 4.

In use, body 52 is slotted into members 32 and 32 a such that thethreaded lugs are located within slots 72. A nut, also not shown, isthen tightened over each threaded lug so as to provide a strongmechanical joint with good electrically conducting properties. Access toapply these nuts is gained through apertures 36.

Referring to FIG. 5, a coupling 80 for joining a first tubularrectangular waterproof trunking member to a second tubular rectangularwaterproof member has a tubular body 82 is adapted to extend partiallyover the first and second members 32 and 32 a. The coupling 80 also hasretaining means, in the form of holes 84, which are adapted to receivescrews 86 which in turn engage with threaded holes 34. Coupling 80 alsohas a neoprene sealing gasket 88.

In use body 82 of coupling 80 is slid over the ends of members 32 and 32a and screws 86 are inserted through holes 84 and tightened in threadedholes 34. As a result a mechanically strong and electrically continuousjoint is provided.

An alternative variation of this coupling is shown in FIG. 6. In thisembodiment the retaining means, shown as holes 34 in FIG. 5 are replacedwith slots 90. The retaining means on body 82 of coupling 80 are fourthreaded lugs 92, only one of which is shown in FIG. 6.

In use, body 82 of coupling 80 is slid over the ends of members 32 and32 a. Threaded lugs 92 are located within slots 90 and a retaining nut,not shown, is tightened over each lug 92. Neoprene seal 88 provides awaterproof contact between body 82 and members 32 and 32 a.

Referring to FIGS. 7 and 9, a coupling 100, for joining a trunkingsection 102 with respective lid 104 and trunking section 106 withrespective lid 108, has a body 110, adapted to be partially receivedwithin trunking sections 102 and 106. Coupling 100 also has firstretaining means, in the form of threaded holes 112, which receiverespective screws, not shown, inserted through holes 113 in trunkingsections 102 and 106. Coupling 100 also has receiving portion 114 whichextends around three sides of body 110 and is adapted to receive edgesof three respective sides of trunking sections 102 and 106 and lids 104and 108. Normally the inserted edges would be the edges of the trunkingsections 102 and 106 and not the edge of lids 104 and 108. For examplethe edges 116, 118 and 120 of trunking section 106 would be receivedwithin receiving portion 114 and edge 122 of lid 108 would not. Coupling100 also has clamping means 124 and second retaining means 126.Receiving portion 114 is provided with a neoprene gasket 128.

In use coupling 100 is brought into engagement with trunking section 102and two screws, not shown, are inserted through holes 113 and engage thethreads in holes 112. Similarly trunking section 106 is engaged withcoupling 100 and two screws are similarly inserted. Cables are then laidin the trunking sections and through the body 110 of coupling 100. Thisis made easier if the upper most surface of body 110 is not present.Lids 104 and 108 are then attached and screwed to trunking sections 102and 106 and clamping means 124 is placed on top and fixed in position bysecond retaining means, screws 126.

Referring to FIG. 10 receiving portion 114 has rounded edges so as toprovide a smooth transition between the surfaces of trunking sections102 and 106 and the surface of receiving portion 114.

An alternative variation of this coupling is shown in FIG. 8. In thisembodiment the retaining means, shown as holes 112 in FIG. 7 arereplaced with slots 130 which are adapted to receive threaded lugs 132and are fixed in position using threaded nuts, not shown.

It will be appreciated by persons skilled in the art that the aboveembodiments have been described by way of example only, and not in anylimitative sense, and that various alterations and modifications arepossible without departure from the scope of the invention as defined bythe appended claims.

1-28. (canceled)
 29. A section of waterproof trunking comprising: atleast one elongate tubular member of substantially rectangularcross-section having at least one attaching device for attaching the oreach said member to at least one further member and having at least oneaperture in at least one respective side of said member for providingaccess to the interior of said member, wherein the or each said aperturehas a length less than the length of the or each said side measured inan axial direction along said tubular member and has a dimension lessthan the dimension of said side measured transverse to said axialdirection; and at least one respective closure device for the or eachsaid aperture.
 30. A section of trunking according to claim 29, whereinat least one said attaching device includes at least one hole in saidmember adapted to receive a respective screw or bolt for retaining themember in position relative to a further member.
 31. A section oftrunking according to claim 29, wherein at least one said attachingdevice is at least one threaded member extending internally from saidmember and adapted to engage a coupling internally of said member, saidcoupling having slots therein allowing said threaded members to passalong said slots.
 32. A section of trunking according to claim 29,wherein at least one said closure device comprises a plate adapted tocover said aperture.
 33. A section of trunking according to claim 32,wherein said plate is provided with a plurality of holes adapted toreceive respective screws or bolts therein for engaging with saidmember.
 34. A section of trunking according to either claim 32 at leastone said cover device further comprising a sealing gasket locatedbetween said plate and said member.
 35. A section of trunking accordingto either claim 33 at least one said cover device further comprising asealing gasket located between said plate and said member.
 36. A sectionof trunking according to claim 29, wherein the axial length of theaperture is less than 50% of the axial length of the member.
 37. Asection of trunking according to claim 29, wherein the axial length ofthe aperture is less than 20% of the axial length of the member.
 38. Acoupling for joining at least one first tubular waterproof trunkingmember of substantially rectangular cross section to at least one secondtubular waterproof trunking member of substantially rectangular crosssection, the coupling comprising: a body adapted to extend within the oreach first and second member; at least one retaining device forretaining said body and the or each said member together; and at leastone extension portion extending around said body and adapted to form asubstantially continuous surface between a surface of said coupling andat least one surface of the or each first member and between a surfaceof said coupling and at least one surface of the or each second member.39. A coupling according to claim 38, wherein edges of said body areshaped so as to provide a substantially smooth transition between aninternal surface of the trunking member and a respective internalsurface of the body.
 40. A coupling according to claim 39, wherein saidedges are curved.
 41. A coupling according to claim 38, wherein at leastone said retaining device comprises a hole in said body adapted to alignwith a hole in a trunking member and adapted to receive a screw or bolttherein.
 42. A coupling according to claim 41, said hole furthercomprising an internal thread.
 43. A coupling according to claim 38,wherein said extension portion is provided with at least one sealingdevice for sealing between the trunking member and the extensionportion.
 44. A coupling according to claim 43, wherein at least one saidsealing device comprises a gasket attached to said extension portion.45. A coupling device for joining at least one first tubular waterprooftrunking member having a rectangular cross section to at least onesecond tubular waterproof trunking member having a rectangular crosssection, the coupling device comprising:— a body adapted to extendwithin the or each first and second member; at least one retainingdevice for retaining said body and the or each said member together; andat least one sealing device extending around said body and adapted toprovide a seal between the or each said first and second member.
 46. Acoupling according to claim 45, wherein edges of said body are shaped soas to provide a smooth transition between an internal surface of thetrunking member and a respective internal surface of the body.
 47. Acoupling according to claim 45, wherein said edges are curved.
 48. Acoupling for joining at least one first tubular waterproof trunkingmember of substantially rectangular cross section to at least one secondtubular waterproof trunking member of substantially rectangular crosssection, the coupling means comprising:— a tubular body, adapted toextend at least partially over the or each first member and at leastpartially over the or each second member; at least one retaining devicefor retaining said body and the or each said member together; and atleast one sealing device for sealing a junction between the first andsecond members.
 49. A coupling according to claim 48, wherein at leastone edge of at least one surface of said body is curved.
 50. A couplingfor joining at least one first trunking member having a lid thereon toat least one second trunking member having a lid thereon, the couplingcomprising:— a body, adapted to extend at least partially within the oreach first and second member; at least one first retaining device forretaining said body and the or each said member together; receivingportion adapted to receive all except one edge of surfaces at an end ofsaid member and said respective lid; at least one clamping deviceadapted to be located over said edge of said member and lid not receivedin said receiving portion; and at least one second retaining device forretaining at least one said clamping device and said retaining portiontogether.
 51. A coupling according to claim 50, wherein said bodyconsists of four surfaces.